66916091816 has 32 divisors (see below), whose sum is σ = 145355903040. Its totient is φ = 28285469568.

The previous prime is 66916091807. The next prime is 66916091881. The reversal of 66916091816 is 61819061966.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8180366 + ... + 8188541.

It is an arithmetic number, because the mean of its divisors is an integer number (4542371970).

Almost surely, 2^66916091816 is an apocalyptic number.

It is an amenable number.

66916091816 is an abundant number, since it is smaller than the sum of its proper divisors (78439811224).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66916091816 is a wasteful number, since it uses less digits than its factorization.

66916091816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16368993 (or 16368989 counting only the distinct ones).

The product of its (nonzero) digits is 839808, while the sum is 53.

The spelling of 66916091816 in words is "sixty-six billion, nine hundred sixteen million, ninety-one thousand, eight hundred sixteen".